Hearing devices are wearable hearing apparatuses which are used to assist the hard-of-hearing. In order to accommodate numerous individual requirements, various types of hearing devices are available such as behind-the-ear hearing devices (BTEs), hearing device with an external receiver (RIC: receiver in the canal) and in-the-ear hearing devices (ITE), for example also concha hearing devices or completely-in-the-canal hearing devices (ITE, CIC). The hearing devices listed as examples are worn on the outer ear or in the auditory canal. Bone conduction hearing aids, implantable or vibrotactile hearing aids are also available on the market. In these devices damaged hearing is stimulated either mechanically or electrically.
The key components of hearing devices are principally an input converter, an amplifier and an output converter. The input converter is normally a receiving transducer e.g. a microphone and/or an electromagnetic receiver, e.g. an induction coil. The output converter is most frequently realized as an electroacoustic converter e.g. a miniature loudspeaker, or as an electromechanical converter e.g. a bone conduction hearing aid. The amplifier is usually integrated into a signal processing unit. This basic configuration is illustrated in FIG. 1 using the example of a behind-the-ear hearing device. One or more microphones 2 for recording ambient sound are built into a hearing device housing 1 to be worn behind the ear. A signal processing unit 3 which is also integrated into the hearing device housing 1 processes and amplifies the microphone signals. The output signal for the signal processing unit 3 is transmitted to a loudspeaker or receiver 4, which outputs an acoustic signal. Sound is transmitted through a sound tube, which is affixed in the auditory canal by means of an otoplastic, to the device wearer's eardrum. Power for the hearing device and in particular for the signal processing unit 3 is supplied by means of a battery 5 which is also integrated in the hearing device housing 1.
Hearing devices with an external receiver have to be embodied such that the receiver is arranged as centrally as possible in the auditory canal during wear. On the other hand, the wearing comfort is reduced and the acoustic characteristics of the device are faulty. With cymba hearing devices, in which the main body of the device including the microphone and signal processing is inserted into the cymba of the concha, the cable to which the external receiver is connected is also used for stabilization purposes. This means that on the one hand the cable exerts forces onto the main body of the hearing device and on the other hand onto the external receiver. This results in the receiver being pressed repeatedly against the wall of the auditory canal, since the earpiece (dome), which is designed to hold the receiver in the auditory canal, consists of relatively soft material. The earpiece is therefore too soft to be able to absorb the forces of the wire and/or cable. The receiver then rests eccentrically in the auditory canal, which, in some circumstances, may result in a significant deterioration of feedback problems.
This problem of the receiver only resting eccentrically in the auditory canal in certain cases was previously not recognized. It was in fact assumed that a standard earpiece centers the receiver precisely in the auditory canal. The situation is somewhat better with so-called active ear mold pieces, which are individually adjusted to the auditory canal. However even these are moved out of their precise position as result of the cable forces, so that problems relating to the centricity of the receiver develop.